Chapter 3 Flashcards
Hypoxia
Lack of dissolved oxygen
Nutrients
Elements and compounds that organisms consumer and are essential for survival
Eutrophication
Process of nutrient over-enrichment in water with hypoxia
System
A network of relationships among parts, elements, or components that interact with and influence each other through the exchange of energy, matter, or info.
Cycles
Flows of chemical elements and compounds that facilitate environmental processes, regulate climate and support life.
Open systems
Receive inputs of energy and matter, and produce outputs of both.
Closed systems
Receive inputs and produce outputs of energy, but not matter. Matter cycles among the system but doesn’t leave or enter it.
Feedback loops
When a system’s output serves as an input to that same system.
- Negative feedback: the outputs from a system become inputs to another system, moving that system in an opposite direction. Here, input and output kind of neutralize each other’s effects, stabilizing the system.
- Positive feedback: rather than stabilizing a system, they drive it further toward one extreme or another. They can alter systems to a great extent. They are rare, but common in natural systems that were altered by human impact.
Dynamic equilibrium
when processes within a system move in opposing directions at equivalent rates so that their effects balance out.
Homeostasis
Tendency of a system to maintain/regulate their internal conditions.
What are the characteristics of homeostatic systems?
- Resistance: the strength of the system’s tendency to remain constant (strength to resist disturbance).
- Resilience: the measure of how fast the system will return to its original state once it has been disturbed.
Emergent properties
Characteristics that are not evident in individual components alone, they arise from the interaction of component parts.
Geosphere
Rock and sediment of the solid earth.
Atmosphere
Thin envelop of gases, water droplets, and dust particles that surrounds our planet.
Hydrosphere
All the water that resides in surface water bodies.
